# name = input()
# print("my name is", name)

# classmates = ['Michael', 'Bob', 'Tracy']
# print(len(classmates))

# names = ('xiaoming', 'xiaohong') # 一个元组

# age = 20
# if age >= 18:
#   print('你是一个成年人了')
# elif age >= 14:
#   print('你是一个青年')
# else:
#   print('你是一个孩子')

def add_end(L = []):
  L.append('END')
  return L

print(add_end(add_end()))